Why This Republican Worries About Climate Change

My recent post advocated getting over Al-Goraphobia and looking at the science, not merely a polarizing political personality. Now it is time to lay out some data. The headlines give a confusing array of information. Are we really cooling? Is ice melting or expanding? It snowed the day Al Gore testified to Congress, does that mean anything?

The effect, perhaps by design, is to leave the reader thinking that nobody really knows what they are talking about. Confident only in confusion, the average American quickly moves on to “real” problems. However, as the wise author Dallas Willard states, “Descending to particulars always helps to clear the mind.”

Why, as a rational Republican, do I believe fighting global warming should be a high priority for our nation?

First, there is no doubt that global temperatures are generally warming. Recent claims that temperatures declined after 1998 are technically true, but recent years are still historically very, very hot. The graph below shows temperatures up to 2005 as it differs from the average for the entire period. The dots are the annual temperature points and the blue line is the smoothed trend-line. Every year since 2005 has been among the top 10 warmest years in thermometer recorded history. Amazingly, the entire top ten falls in the years since 1997.

As you can see, the “decline” trumpeted by some (the slight dip after 1998) is about as convincing as the recent “rise” in the stock market since its November low. Financially, we are still in a big bear market even if on some days the Dow is up 3%, and climatically we are still in a warming trend even if each and every consecutive year is not hotter than before.

Second, with solid science dating back to 1827, there is no debating that carbon dioxide (CO2) is a greenhouse gas. And thank goodness it is. The greenhouse effect, fueled primarily by CO2 and water vapor, has produced a temperature range favorable for life.

But, the greenhouse effect can get out of control. The CO2 rich atmosphere of Venus blocks most solar radiation from making it to the surface, but that energy is then trapped by the greenhouse effect. The net impact is a temperature increase of 500 degrees C. Venus is nearly three times hotter than the thinly CO2 blanketed Mercury, even though Mercury is closer to the Sun.

There are a number of cycles that naturally affect the Earth’s temperature, related to the Earth’s axis wobbling, cycles within our orbit, sun spots, etc. Yet, through these cycles a clear correlation exists between CO2 and temperature. The interrelationship is complex and it is true that temperature can in certain situations “lead” and result in releases of CO2 from the carbon “sink” of the oceans. The full impact from a variety of positive and negative feedback loops is difficult to precisely estimate, but the basic theory that more CO2 helps trigger higher temperatures is quite sound.

Third, there is no doubt that CO2 levels have been rising since the industrial revolution. It is not hard to see why: tons and tons of carbon have been transferred by combustion from a solid (coal) or liquid (oil) or underground gas (natural gas) to atmospheric CO2.

The graph below captures the correlation between CO2 and temperature well. (Note: The pre-thermometer information is largely based on ice core analysis.) The graph also highlights the reason for concern. For hundreds of thousands of years, CO2 has ranged between about 180 and 300 parts per million (ppm). Currently we are at 385 ppm , and with each SUV trip to grocery store and new Chinese coal power plant we all contribute, in big and small ways, to a rapid rate of increase.

Frankly, no one knows what the future holds at 500 or 600 ppm, but we can surmise that it probably will not be good. Our societies have been built on a framework of climatic stability. Coastal cities expect the oceans to stay about where they are. African farmers expect the rains to come just as they did for their ancestors. South American kids expect that malarial mosquitoes will stay at lower elevations like they always have. But change is coming, and at a pace that is unprecedented in human history. Acting now can soften the blow.

In a nutshell, that is why I am concerned---for myself and all who will call Earth home in the future.

(Note: Some of the information in this post is taken from Global Warming: The Complete Briefing by Sir John Houghton, an atmospheric physicist who is also an evangelical Christian and former adviser to Margaret Thatcher.)